1. Field of the Invention
The present invention relates to a cylindrical member, an electrophotographic photosensitive drum, a developing roller, and a process cartridge.
The cylindrical member, the electrophotographic photosensitive drum, and the developing roller are used in an electrophotographic image forming apparatus. The electrophotographic image forming apparatus forms an image on a recording medium by an electrophotographic image forming method. Examples of an electrophotographic image forming apparatus include electrophotographic copiers, electrophotographic printers (for example, laser beam printers, LED printers, etc.), facsimile machines, word processors, and so on.
2. Related Background Art
The conventional electrophotographic image forming apparatus employing the electrophotographic image forming process uses cylindrical members such as an electrophotographic photosensitive drum or the developing roller. An engaging member so called as a drum flange or the like is attached to an end of these cylindrical members.
An example of the electrophotographic photosensitive drum will be described as a typical example. This electrophotographic photosensitive drum is constructed in such an arrangement that the engaging member, e.g., a drum gear and a drum flange, for receiving a driving force for rotating the photosensitive drum is coupled with an end of a cylinder, the surface of which is coated with a photosensitive, electroconductive material.
A method for coupling the cylinder with the engaging member is the method shown in European Patent Publication No. 0 528 568 Al, in which the engaging member provided with a depression is inserted into the end of a cylinder. Then the end of the cylinder is cut and bent to achieve coupling.
Another method is the method shown in Japanese Laid-open Patent Application No. 6-264920, in which the internal surface of the cylinder is first subjected to the spigot joint processing. Then, the engaging member is engaged with the internal surface of the cylinder. Then, the cylinder is cut and bent at a plurality of portions thereof to engage the cut and bent portions with a depression of the engaging member.